How SuperCroc and its Ancient Cousins Survived a Mass Extinction

New Discoveries Lead to Insights on Species Evolution

by Max Lien, age 13

Ten years ago, Paul Sereno of the University of Chicago led a team of paleontologists into the Sahara Desert. During the expedition, these scientists found the remains of the largest known crocodile ever to walk the Earth. They dubbed their new discovery SuperCroc.

The fossilized remains discovered by Sereno and his team are 110 million years old. We now know that SuperCroc was 440 feet long and weighed eight tons. It was also one of the most dangerous and successful predators of its time.

Now, a new expedition—including Sereno and many of the same scientists—has discovered four additional crocodile fossils in the same area where SuperCroc was found. These newly discovered fossils are named RatCroc, DuckCroc, BoarCroc, and PancakeCroc.

These new discoveries are helping scientists prove a very important and somewhat controversial theory. Paleontologists believe that some reptile species survived the extinction of the dinosaurs. Most of course, did not.

Discovered on a previous expedition, another fossil, DogCroc, is considered to be a similar or related species to RatCroc, DuckCroc, BoarCroc, and PancakeCroc. Scientists are still sorting out which of these are distinct species and which of these survived the dinosaur extinction that occurred about 65 million years ago.

These odd names were invented to reflect the features on the snouts of the crocodiles. The distinct features of their skulls remind paleontologists of these more modern and common things. DogCroc, RatCroc, and DuckCroc were relatively small, each about three feet long. BoarCroc and PancakeCroc were much larger, both almost 20 feet long.

DogCroc had a forward pointing snout like a dog and ate fish, frogs and grubs, while RatCroc consumed roots using its lower jaw to dig in the ground. DuckCroc ate plants, grubs, fish and frogs like DogCroc, but had a snout that gave it the ability to feel for its prey while hunting.

As a large carnivore, BoarCroc had an armored snout for ramming its prey and three sets of dagger-shaped teeth for slicing meat. PancakeCroc was the only one of these crocodiles that was not an upright species. It also ate plants and grubs like the DogCroc; unlike the DogCroc, however, it had a long, flattened jaw.

Paleontologists hope to find more ancient crocodile fossils in the future. By studying these fossils, they can soon understand the characteristics and adaptations of these ancient species and how the process of evolution turned them into modern crocodiles.